Fiendishly Challenging Movie Trivia

I had long been aware that this famous movie included the very first film appearance of Jeff Goldblum (as a vicious thug) as well as one of the first screen roles of Christopher Guest (as a police officer). But it was pointed out to me yesterday that it was also the first — though uncredited — screen appearance of Denzel Washington!

Without googling, IMDBing or other cheating, take a guess. (Answer after the jump).